The ambient solar wind is made of a variety of streams and structures whose properties cover a wide range of values depending on several aspects: origin of the wind at the Sun, but also acceleration processes, turbulence, and stream-stream interactions (see review by [1]}). It is therefore challenging to relate solar wind bulk properties measured near 1 AU (e.g. [2]}) to clearly defined coronal sources. Composition and suprathermal electron measurements have remained for a long time the most relevant wind measurements to probe source-dependent effects [3]}.
Parker Solar Probe (PSP) is measuring solar wind plasma and magnetic field with both remote and in situ instruments, closer to the Sun than any probe before since its first perihelion on November 5, 2018. During encounter 2 (E2), whose perihelion took place on April 5, 2019, PSP measured essentially slow solar wind (with a speed slower than \(500~\mathrm {km.s^{-1}}\) ).
